1. Field of the Invention
The present invention relates to processing systems and more particularly, but not necessarily exclusively to welding systems to manufacture tailored blanks.
2. Description of the Related Art
The automobile industry has, over the years, achieved significant improvements in the operating efficiency of the automobiles they produce. This has, in large part, been achieved by the reduction in the weight of the vehicle while maintaining its structural integrity. A major proportion of the weight of the vehicle is from its steel components, such as the chassis and doors, hood and trunk lids. Often, there are areas in the structure of these components that need to remain of a greater thickness, such as in the region of the door hinges, while there are other areas, such as in the door frame, that can be of relatively thinner wall. It is common in this case to reinforce the otherwise relatively thin door frame in the regions to carry the hinges with a stiffener to provide the necessary reinforcement. However, this step increases the parts count and is a source for additional cost.
The automobile industry has, in recent years, been working to implement a welding process to fabricate what is popularly known as a tailored blank which has a relatively thick portion which is welded to a relatively thin portion, so that it can be later stamped into a part with a thick portion being in place to provide strength, reduce the overall part count and weight.
A significant improvement to laser welding lines is disclosed in U.S. Pat. No. 6,204,469 entitled LASER WELDING SYSTEM, assigned to HONDA GIKEN KOGYC KABUSHIKI KAISHA. The subject matter of this patent is incorporated herein by reference. This will be referred to as the Honda '469 patent.
While the system described in the '469 patent has provided a substantial increase in the speed, accuracy and integrity of tailored blanking welds, there is a continuing need to make further improvements, particularly in the speed of the operation.
Accordingly, the present invention seeks to improve certain aspects of the welding processes such as those used to form tailored blanks.